1. Field of the Invention
The present invention relates to a high-pressure processing apparatus and a high-pressure processing method which subject a surface of a process subject to a predetermined surface treatment by allowing a process fluid to contact the surface of the process subject, the process fluid comprising a high-pressure fluid or a mixture of the high-pressure fluid and a chemical agent. The process subject includes a variety of substrates such as semiconductor wafers, glass substrates for photomask, glass substrates for liquid crystal display, glass substrates for plasma display, and optical disk substrates (hereinafter, simply referred to as “substrate”).
2. Description of the Related Art
In a case where a resist is used for forming a pattern in a semiconductor fabrication process, a cleaning step is required for removing unwanted substances and contaminants from the substrate, the unwanted substances and contaminants including the resist becoming no more necessary after the pattern formation, etching polymer produced during an etching process and remaining on the substrate, and the like. Hence, a high-pressure processing apparatus is known which performs the cleaning process on the substrate by exposing the substrate surface to the process fluid comprising the mixture of the high-pressure fluid and the chemical agent.
In a high-pressure processing apparatus disclosed in Japanese Unexamined Patent Publication No. 2002-313764 (hereinafter, referred to as “Patent Document 1”), the cleaning of the substrate is performed by supplying a process fluid to a processing chamber with the substrate set therein, the process fluid comprising a mixture of a high-pressure fluid and a plurality of chemical agents. More specifically, the high-pressure processing apparatus includes: high-pressure fluid supply means for supplying the high-pressure fluid to the processing chamber; first chemical-agent supply means for supplying a first chemical agent to the processing chamber; and second chemical-agent supply means for supplying a second chemical agent to the processing chamber. These supply means are each provided with a pressure pump (high-pressure pump) in order to pump the high-pressure fluid or the chemical agent to the processing chamber.
The above high-pressure processing apparatus of Patent Document 1 requires the pressure pumps to be provided by the number of types of the chemical agents because the chemical-agent supply means is provided in correspondence to each chemical agent to be admixed with the high-pressure fluid. The pressure pump is generally expensive and hence, the increase in the number of pressure pumps provided directly results in an increased cost of the high-pressure processing apparatus. Particularly, there is a tendency to use an increasing number of chemical agents for the purpose of improving the versatility or performance of the high-pressure processing apparatus. This tendency constitutes one of major factors increasing the fabrication costs of the high-pressure processing apparatus.
Furhtermore, the high-pressure processing apparatus need be so arranged as to pump the plural chemical agents from the respective pressure pumps and to supply all or selected one(s) of the chemical agents to the processing chamber. On this account, there are provided high-pressure valves and high-pressure pipes between the individual pressure pumps and the processing chamber. This entails a similar problem to the above. That is, as the number of types of used chemical agents increases, the number of components, such as the high-pressure valve and the high-pressure pipe, increases correspondingly. This results in the increased fabrication costs of the high-pressure processing apparatus. Furthermore, the pipe line is complicated, leading to another problem that the construction of the apparatus is complicated.